Last-Modified & 304 Checker
Checks conditional caching: Last-Modified / ETag and the 304 Not Modified response. Clear verdict.
ℹ️ A properly configured server must return 304 Not Modified (no body) on a conditional request when the page has not changed. The check runs from our server.
FAQ
What does this tool check?
Whether the server sends a Last-Modified (or ETag) header and returns 304 Not Modified to a conditional If-Modified-Since / If-None-Match request when the page has not changed. The 304 response must have no body.
Why does it matter for SEO and speed?
If the server returns 304, the browser and crawler do not re-download the page — bandwidth and crawl budget are saved and the site loads faster. A direct quality signal for Google and Yandex.
What does the verdict mean?
“Perfect” — a validator is present and the server correctly returns 304. “Not good” — the header is present but no 304 (the server re-sends the page). “Bad” — neither Last-Modified nor ETag is configured.
How is the result proven?
The tool shows the actual Last-Modified and ETag values, the conditional-request status code (304 or 200) and the response body size — on a 304 the body must be empty (0 bytes).